diff options
Diffstat (limited to 'arch/arm/plat-stmp3xxx/timer.c')
| -rw-r--r-- | arch/arm/plat-stmp3xxx/timer.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/arch/arm/plat-stmp3xxx/timer.c b/arch/arm/plat-stmp3xxx/timer.c new file mode 100644 index 000000000000..c916068f0cab --- /dev/null +++ b/arch/arm/plat-stmp3xxx/timer.c @@ -0,0 +1,172 @@ +/* + * System timer for Freescale STMP37XX/STMP378X + * + * Embedded Alley Solutions, Inc <source@embeddedalley.com> + * + * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/interrupt.h> + +#include <asm/mach/time.h> +#include <mach/stmp3xxx.h> +#include <mach/regs-timrot.h> + +static irqreturn_t +stmp3xxx_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *c = dev_id; + + if (HW_TIMROT_TIMCTRLn_RD(0) & (1<<15)) { + HW_TIMROT_TIMCTRLn_CLR(0, (1<<15)); + c->event_handler(c); + } else if (HW_TIMROT_TIMCTRLn_RD(1) & (1<<15)) { + HW_TIMROT_TIMCTRLn_CLR(1, (1<<15)); + HW_TIMROT_TIMCTRLn_CLR(1, BM_TIMROT_TIMCTRLn_IRQ_EN); + HW_TIMROT_TIMCOUNTn_WR(1, 0xFFFF); + } + + return IRQ_HANDLED; +} + +static cycle_t stmp3xxx_clock_read(void) +{ + return ~((HW_TIMROT_TIMCOUNTn_RD(1) & 0xFFFF0000) >> 16); +} + +static int +stmp3xxx_timrot_set_next_event(unsigned long delta, + struct clock_event_device *dev) +{ + HW_TIMROT_TIMCOUNTn_WR(0, delta); /* reload */ + return 0; +} + +static void +stmp3xxx_timrot_set_mode(enum clock_event_mode mode, + struct clock_event_device *dev) +{ +} + +static struct clock_event_device ckevt_timrot = { + .name = "timrot", + .features = CLOCK_EVT_FEAT_ONESHOT, + .shift = 32, + .set_next_event = stmp3xxx_timrot_set_next_event, + .set_mode = stmp3xxx_timrot_set_mode, +}; + +static struct clocksource cksrc_stmp3xxx = { + .name = "cksrc_stmp3xxx", + .rating = 250, + .read = stmp3xxx_clock_read, + .mask = CLOCKSOURCE_MASK(16), + .shift = 10, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +static struct irqaction stmp3xxx_timer_irq = { + .name = "stmp3xxx_timer", + .flags = IRQF_DISABLED | IRQF_TIMER, + .handler = stmp3xxx_timer_interrupt, + .dev_id = &ckevt_timrot, +}; + + +/* + * Set up timer interrupt, and return the current time in seconds. + */ +static void __init stmp3xxx_init_timer(void) +{ + cksrc_stmp3xxx.mult = clocksource_hz2mult(CLOCK_TICK_RATE, + cksrc_stmp3xxx.shift); + ckevt_timrot.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, + ckevt_timrot.shift); + ckevt_timrot.min_delta_ns = clockevent_delta2ns(2, &ckevt_timrot); + ckevt_timrot.max_delta_ns = clockevent_delta2ns(0xFFF, &ckevt_timrot); + ckevt_timrot.cpumask = cpumask_of(0); + + HW_TIMROT_ROTCTRL_CLR(BM_TIMROT_ROTCTRL_SFTRST | + BM_TIMROT_ROTCTRL_CLKGATE); + HW_TIMROT_TIMCOUNTn_WR(0, 0); + HW_TIMROT_TIMCOUNTn_WR(1, 0); + + HW_TIMROT_TIMCTRLn_WR(0, + (BF_TIMROT_TIMCTRLn_SELECT(8) | /* 32 kHz */ + BF_TIMROT_TIMCTRLn_PRESCALE(0) | + BM_TIMROT_TIMCTRLn_RELOAD | + BM_TIMROT_TIMCTRLn_UPDATE | + BM_TIMROT_TIMCTRLn_IRQ_EN)); + HW_TIMROT_TIMCTRLn_WR(1, + (BF_TIMROT_TIMCTRLn_SELECT(8) | /* 32 kHz */ + BF_TIMROT_TIMCTRLn_PRESCALE(0) | + BM_TIMROT_TIMCTRLn_RELOAD | + BM_TIMROT_TIMCTRLn_UPDATE)); + + HW_TIMROT_TIMCOUNTn_WR(0, CLOCK_TICK_RATE / HZ - 1); + HW_TIMROT_TIMCOUNTn_WR(1, 0xFFFF); /* reload */ + + setup_irq(IRQ_TIMER0, &stmp3xxx_timer_irq); + + clocksource_register(&cksrc_stmp3xxx); + clockevents_register_device(&ckevt_timrot); +} + +#ifdef CONFIG_PM + +void stmp3xxx_suspend_timer(void) +{ + HW_TIMROT_TIMCTRLn_CLR(0, BM_TIMROT_TIMCTRLn_IRQ_EN); + HW_TIMROT_TIMCTRLn_CLR(0, (1<<15)); + HW_TIMROT_ROTCTRL_SET(BM_TIMROT_ROTCTRL_CLKGATE); +} + +void stmp3xxx_resume_timer(void) +{ + HW_TIMROT_ROTCTRL_CLR(BM_TIMROT_ROTCTRL_SFTRST | + BM_TIMROT_ROTCTRL_CLKGATE); + + + HW_TIMROT_TIMCTRLn_WR(0, + (BF_TIMROT_TIMCTRLn_SELECT(8) | /* 32 kHz */ + BF_TIMROT_TIMCTRLn_PRESCALE(0) | + BM_TIMROT_TIMCTRLn_UPDATE | + BM_TIMROT_TIMCTRLn_IRQ_EN)); + HW_TIMROT_TIMCTRLn_WR(1, + (BF_TIMROT_TIMCTRLn_SELECT(8) | /* 32 kHz */ + BF_TIMROT_TIMCTRLn_PRESCALE(0) | + BM_TIMROT_TIMCTRLn_RELOAD | + BM_TIMROT_TIMCTRLn_UPDATE)); + + HW_TIMROT_TIMCOUNTn_WR(0, CLOCK_TICK_RATE / HZ - 1); + HW_TIMROT_TIMCOUNTn_WR(1, 0xFFFF); /* reload */ +} + +#else + +#define stmp3xxx_suspend_timer NULL +#define stmp3xxx_resume_timer NULL + +#endif /* CONFIG_PM */ + +struct sys_timer stmp3xxx_timer = { + .init = stmp3xxx_init_timer, + .suspend = stmp3xxx_suspend_timer, + .resume = stmp3xxx_resume_timer, +}; |